<?php

/**
 * This is the model class for table "{{tag}}".
 *
 * The followings are the available columns in table '{{tag}}':
 * @property integer $id
 * @property string $name
 * @property integer $frequency
 */
class Tag extends CActiveRecord
{

  // viennp them vo
  public static function string2array($tags)
  {
    return preg_split('/ns*,ns*/',trim($tags),-1,PREG_SPLIT_NO_EMPTY);
  }
  public static function array2string($tags)
  {
    return implode(', ',$tags);
  }



  /** vienp
   * Returns tag names and their corresponding weights.
   * Only the tags with the top weights will be returned.
   * @param integer the maximum number of tags that should be returned
   * @return array weights indexed by tag names.
   */
  public function findTagWeights($limit=20)
  {
    $models=$this->findAll(array(
        'order'=>'frequency DESC',
        'limit'=>$limit,
    ));

    $total=0;
    foreach($models as $model)
      $total+=$model->frequency;

    $tags=array();
    if($total>0)
    {
      foreach($models as $model)
        $tags[$model->name]=8+(int)(16*$model->frequency/($total+10));
      ksort($tags);
    }
    return $tags;
  }

  /** viennp
   * Suggests a list of existing tags matching the specified keyword.
   * @param string the keyword to be matched
   * @param integer maximum number of tags to be returned
   * @return array list of matching tag names
   */
  public function suggestTags($keyword,$limit=20)
  {
    $tags=$this->findAll(array(
        'condition'=>'name LIKE :keyword',
        'order'=>'frequency DESC, Name',
        'limit'=>$limit,
        'params'=>array(
            ':keyword'=>'%'.strtr($keyword,array('%'=>'\%', '_'=>'\_', '\\'=>'\\\\')).'%',
        ),
    ));
    $names=array();
    foreach($tags as $tag)
      $names[]=$tag->name;
    return $names;
  }

  //viennp
  public function updateFrequency($oldTags, $newTags)
  {
    $oldTags=self::string2array($oldTags);
    $newTags=self::string2array($newTags);
    $this->addTags(array_values(array_diff($newTags,$oldTags)));
    $this->removeTags(array_values(array_diff($oldTags,$newTags)));
  }

  //viennp
  public function addTags($tags)
  {
    $criteria=new CDbCriteria;
    $criteria->addInCondition('name',$tags);
    $this->updateCounters(array('frequency'=>1),$criteria);
    foreach($tags as $name)
    {
      if(!$this->exists('name=:name',array(':name'=>$name)))
      {
        $tag=new Tag;
        $tag->name=$name;
        $tag->frequency=1;
        $tag->save();
      }
    }
  }

  //viennp
  public function removeTags($tags)
  {
    if(empty($tags))
      return;
    $criteria=new CDbCriteria;
    $criteria->addInCondition('name',$tags);
    $this->updateCounters(array('frequency'=>-1),$criteria);
    $this->deleteAll('frequency<=0');
  }

  /**
   * Returns the static model of the specified AR class.
   * @param string $className active record class name.
   * @return Tag the static model class
   */
  public static function model($className=__CLASS__)
  {
    return parent::model($className);
  }

  /**
   * @return string the associated database table name
   */
  public function tableName()
  {
    return '{{tag}}';
  }

  /**
   * @return array validation rules for model attributes.
   */
  public function rules()
  {
    // NOTE: you should only define rules for those attributes that
    // will receive user inputs.
    return array(
        array('name', 'required'),
        array('frequency', 'numerical', 'integerOnly'=>true),
        array('name', 'length', 'max'=>128),
        // The following rule is used by search().
        // Please remove those attributes that should not be searched.
        array('id, name, frequency', 'safe', 'on'=>'search'),
    );
  }

  /**
   * @return array relational rules.
   */
  public function relations()
  {
    // NOTE: you may need to adjust the relation name and the related
    // class name for the relations automatically generated below.
    return array(
    );
  }

  /**
   * @return array customized attribute labels (name=>label)
   */
  public function attributeLabels()
  {
    return array(
        'id' => 'ID',
        'name' => 'Name',
        'frequency' => 'Frequency',
    );
  }

  /**
   * Retrieves a list of models based on the current search/filter conditions.
   * @return CActiveDataProvider the data provider that can return the models based on the search/filter conditions.
   */
  public function search()
  {
    // Warning: Please modify the following code to remove attributes that
    // should not be searched.

    $criteria=new CDbCriteria;

    $criteria->compare('id',$this->id);
    $criteria->compare('name',$this->name,true);
    $criteria->compare('frequency',$this->frequency);

    return new CActiveDataProvider($this, array(
        'criteria'=>$criteria,
    ));
  }
}